PHOTOSYNTHESIS

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  • Created by: Lily04
  • Created on: 14-06-17 19:18
Recall the word equation for photosythesis
carbon dioxide + water > glucose + oxygen
1 of 20
Why do plants grow faster in summer rather than winter?
The higher temperature increases the rate of reaction of enzymes involved in photosythesis.
2 of 20
True of False? Plants only photosynthesize, they do not respire
False: plants DO carry out respiration
3 of 20
Recall the balanced symbol equation for photosythesis
6C02 + 6H20 > C6H1206 + 602
4 of 20
Describe the discovery of the Greek scientist Van Helmont and what date?
1600- he grew a willow tree in a plant pot for 5 years. It showed a large increase in mass but there was little mass change in the soil. The increase could not solely be due to soil minerals.
5 of 20
Describe the discovery of the Greek scientist Joseph Priestly and state a date.
1771- put a part of a mint plant in a transparent closed space with a burning candle (which used up the oxygen). After 27 days he was able to relight the candle. The plant had produced gas (oxygen)
6 of 20
State the 3 factors that increase the rate of photosynthesis
light intensity, temperature, C02 concentration
7 of 20
What affect does light intensity have on photosynthesis?
light intensity increases=rate is up-it is the limiting factor up to a certain point but after this point, a rise in light intensity has no effect; therefore, light intensity cannot be the limiting factor, something else must be such as C02 or temp.
8 of 20
What affect does C02 concentration have on the rate of photosynthesis?
Increases the rate but after a certain point, a rise in C02 levels have no effect therefore temperature or light must be the limiting factor
9 of 20
What affect does temperature have on rate of photosynthesis?
As temp rises, the rate also increases BUT when temp. approaches 45 the enzymes controlling photosynthesis start to denature and rate declines to 0.
10 of 20
Why do plants carry out respiration at all times?
Unlike photosynthesis, respiration never stops because the plant needs the constant supply of energy it releases to remain alive
11 of 20
Explain the differences in gaseous exchange in plants during day and night.
DAY: as long as a plant is photosynthesising it needs to take in c02 through its leaves. At the same time it will release oxygen. NIGHT: the plant still needs oxygen for respiration. It takes in 02 from the air and releases C02.
12 of 20
Photosynthesis is a two stage process. Explain this.
Experiments using isotopes have shown that the light energy is used to split water, not C02 as originally thought. The water is split up into oxygen gas and hydrogen ions. C02 gas then combines with the H2 from the split up water, forming glucose.
13 of 20
How did they discover that photosynthesis is a two stage process?
using radioactive oxygen-18, scientists discovered that 02 as a by-product of photosynthesis comes from the water and not the C02. Only when oxygen-18 is put in via the water do you get radioactive waste product of 02.
14 of 20
What was the single-celled green algae called that was used in experiments on photosynthesis?
Chlorella
15 of 20
The glucose produced by photosynthesis can be used in two ways.....
used immediately to produce energy through respiration OR can be converted into other substances that the plant needs
16 of 20
What can glucose and starch be converted into? Give 3 things.
cellulose to make new cell walls, proteins for growth and repair, fats and oils are stored for future use.
17 of 20
Fill in the gaps: Glucose is ..... it can be transported around the plant as a soluble sugar, but it must be..... into..... which is...... in order for it to be ......
SOLUBLE / CONVERTED / STARCH / INSOLUBLE / STORED
18 of 20
Explain why starch is a very useful storage molecule.
insoluble so it doesn't affect water concentration- does not move away in solution from storage areas.
19 of 20
If cells stored soluble glucose, what would happen?
the inside of cells would be very concentrated and water would constantly move in through osmosis, causing the cell to the swell.
20 of 20

Other cards in this set

Card 2

Front

Why do plants grow faster in summer rather than winter?

Back

The higher temperature increases the rate of reaction of enzymes involved in photosythesis.

Card 3

Front

True of False? Plants only photosynthesize, they do not respire

Back

Preview of the front of card 3

Card 4

Front

Recall the balanced symbol equation for photosythesis

Back

Preview of the front of card 4

Card 5

Front

Describe the discovery of the Greek scientist Van Helmont and what date?

Back

Preview of the front of card 5
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